Deck stairs over existing stone retaining wall steps

I have a deck that is being built outside of a walk out basement. The property slopes so there is a mortared natural stone retaining wall that the back of the house is on. The retained area goes out maybe 20 feet from the back of the house leading to a 2 or 3 foot high retaining wall which then steps down to the yard. The deck contractor is planning to build a wooden stair case that is basically right over those 3 stone steps; tucking them into the stone stairwell. Is this ok? Should I be very concerned about needing to repair the loose mortar in the future? The wall in general is in good shape, but over time, the mortar tends to come loose in some areas (mostly near the top layer of the wall).

It's night here, so can't get a good picture but I did find this online. This is NOT my house, but the wall and steps are similar to what I have in the back yard, imagine a string of steps with railings floating above the stone wall steps connecting to a deck.

So you would walk down wood stairs and then be walking down stone stairs? If this is the case the RISE/RUN MUST be identical to be code compliant (within 3/8" of each other) this might be kind of hard to do. I don't like that transition without a landing (min 36" long x width of the stairs).

Ok, not what I was picturing in my mind. No problem in covering the stone steps. That cantilever is mighty large (too big) is he planning on adding more posts on that stair platform? (upper deck)

I don't think so, we cut the preciously existing upper deck back 14 inches to avoid needing additional footings. I assume there will be some smaller support posts though. If its messed up, wouldn't it fail inspection?

I don't think so, we cut the preciously existing upper deck back 14 inches to avoid needing additional footings. I assume there will be some smaller support posts though. If its messed up, wouldn't it fail inspection?

It could be the perspective of the camera but it looks like a 6' cantilever and then stairs hanging off it as well, I've seen large cantilevers like that with a set of stairs hanging and they usually sag later.

To be honest... I'm not wild about it, I'm not wild about it WITHOUT hanging a heavy set of stairs off it, once you add the stairs in there is a lot more weight there. It will be fine for a couple years, but likely down the road it will begin to sag.
If I HAD to build it that way then I would make every joist that cantilevers 4' a double joist, and possibly the one with the stairs would be a triple.

BUT... that is me and the way I build.

I'm sure your contractor would hate me if you brought this up (much like I would not be happy if one of my customers said "this guy on the internet said...")